by RickRackstop
You say competing engines, you really need to compare identical engines. I know of 2 sets of test done by Southwest Research: the first on an Ingram Barge engine a 12-710G. they tested 5 configurations, the first 4 were with different injectors with different timing. The fifth they added a Firwin catalyst in place of the exhaust manifold and the fuel consumption went up 7%. That was before it could get plugged up. The other was a test on switcher locomotives and the internal structure kept collapsing plugging the exhaust. In any case they will increase the back pressure reducing turbo efficiency. So lets say I'm highly skeptical.
One thing that I wonder about is how Cummins got this deal without a prototype engine and with little or no real locomotive experience. EMD could counter offer to upgrade the existing engines with the Tier 4 parts when available. Cummins does have a relationship with NREC so maybe they are supposed to do the engineering work. It wasn't that long ago that EMD was on the market I guess CAT beat them to the punch.
One thing that I wonder about is how Cummins got this deal without a prototype engine and with little or no real locomotive experience. EMD could counter offer to upgrade the existing engines with the Tier 4 parts when available. Cummins does have a relationship with NREC so maybe they are supposed to do the engineering work. It wasn't that long ago that EMD was on the market I guess CAT beat them to the punch.